During the past 50 years, leadership scholars have conducted more than 1,000 studies in an attempt to determine the definitive styles, characteristics, or personality traits of great leaders. None of these studies has produced a clear profile of the ideal leader. Thank goodness. If scholars had produced a cookie-cutter leadership style, individuals would be forever trying to imitate it. They would make themselves into personae, not people, and others would see through them immediately.

A version of this article appeared in the February 2007 issue of Harvard Business Review.